Multielectrode Catheter Research Articles

Novel Mapping Strategies for Ventricular Tachycardia Ablation.

Despite advances in antiarrhythmic and device therapy, ventricular tachycardia (VT) continues to be a major cause of increased morbidity and mortality. During scar-mediated monomorphic ventricular tachycardia ablation, the search for critical isthmus sites continues to be the primary goal during successful ablative procedures. However, given the overwhelming hemodynamic instability of most ventricular arrhythmias (> 70%), VT ablation is increasingly performed during sinus rhythm. This technique requires either a greater reliance on isthmus surrogates, or more extensive ablation techniques and is a more probabilistic approach to substrate modification. We believe that a better understanding of scar physiology and activation during sinus rhythm has important implications for clinical workflow and mechanistic improvements with current ablation strategies. With advancements in high-density mapping and multi-electrode catheter technology, mapping of VT substrates is performed with higher resolution, with improved visualization of local abnormal ventricular activities (LAVA), and with a more nuanced functional understanding of late potentials. As a prerequisite, our practice for VT ablation starts with a high-density structural map to identify voltage abnormalities as well as an isochronal functional map of sinus rhythm activation to identify region of discontinuous wavefront propagation. As the era of increased automation has emerged, there continues to be vast array of customizable features, and we have adopted the use of multiple wavefront mapping to further elucidate possible arrhythmogenic substrate. Our emerging understanding of how scar propagation patterns relate to areas of abnormal signals and critical isthmuses may greatly improve the ability to identify surrogates during sinus rhythm and help localize the most arrhythmogenic regions within a given scar. In the hemodynamically unstable patients, we routinely integrate isochronal late activation mapping (ILAM) to identify areas of slow conduction to initiate our targeted ablation and substrate modification. Multi-electrode delineation of the entire reentrant VT circuit has value in understanding the size of the circuit, rotational nature, and transmural extent of human reentry. Correlative studies between the activation of the complete VT circuit and sinus rhythm are likely to provide important mechanistic insights on where fixed and/or functional block occurs within a complex scar substrate.

Real-Time Rotational Activity Detection in Atrial Fibrillation.

Rotational activations, or spiral waves, are one of the proposed mechanisms for atrial fibrillation (AF) maintenance. We present a system for assessing the presence of rotational activity from intracardiac electrograms (EGMs). Our system is able to operate in real-time with multi-electrode catheters of different topologies in contact with the atrial wall, and it is based on new local activation time (LAT) estimation and rotational activity detection methods. The EGM LAT estimation method is based on the identification of the highest sustained negative slope of unipolar signals. The method is implemented as a linear filter whose output is interpolated on a regular grid to match any catheter topology. Its operation is illustrated on selected signals and compared to the classical Hilbert-Transform-based phase analysis. After the estimation of the LAT on the regular grid, the detection of rotational activity in the atrium is done by a novel method based on the optical flow of the wavefront dynamics, and a rotation pattern match. The methods have been validated using in silico and real AF signals.

Correlation of right ventricular multielectrode endocardial unipolar mapping and epicardial scar.

Prior studies identified a relationship between epicardial bipolar and endocardial unipolar voltage. Whether the relationship is valid with smaller multielectrode mapping catheters has not been reported. We explored the association of right ventricular (RV) endocardial unipolar voltage mapping with epicardial bipolar voltage mapping using a multielectrode mapping catheter. Electrograms from patients who underwent multielectrode endocardial and epicardial RV electroanatomical mapping during ablation procedures were analyzed. Each endocardial mapping point was matched to the corresponding nearest epicardial point. The correlation between unipolar endocardial voltage and epicardial bipolar voltage was determined. The optimal unipolar threshold to detect epicardial low voltage(<1.0mV) and dense scar (0.5mV) was calculated. A total of 4,895 points were analyzed. There was a significant correlation between endocardial unipolar and epicardial bipolar voltage (Spearman rho=0.499, P=<0.001). The extent of the correlation was inversely associated with wall thickness. The receiver operator characteristic analysis of endocardial unipolar voltage predicting epicardial bipolar voltage of<1.0mV and<0.5 showed an area under the curve of 0.769 and 0.812, respectively. The endocardial unipolar voltage that had the highest sensitivity and specificity in detecting epicardial bipolar voltage of<1.0mV and<0.5mV was 3.3mV (70.3% sensitivity, 70.3% specificity), and 2.8mV (sensitivity 73.8%, specificity 73.3%), respectively. Epicardial low voltage of the RV can be assessed by unipolar endocardial voltage using small multielectrode catheters. The strength of the association was inversely correlated with the wall thickness.

QUALITY OF LIFE POST AF ABLATION AND RELATIONSHIP TO OUTCOME AND AF BURDEN

Atrial fibrillation (AF) significantly impairs patients’ quality of life (QOL) and has a great effect on health care resource utilization (HCU). We performed a study to compare the effect of a multi-electrode Pulmonary Vein Ablation Catheter (PVAC) vs. traditional point-by-point AF ablation

Point-by-point versus multisite electrode mapping in VT ablation: does freedom from VT recurrences depend on mapping catheter? An observational study.

This study was conducted with the purpose of determining whether or not the potential technical advantages of multi-electrode mapping catheters in catheter ablation (CA) of ventricular tachycardia (VT) result in any relevant clinical benefit for VT patients. A single-center VT study, having taken place from 2012 to 2014 using a standard 3.5-mm catheter (Thermocool SF® group 1) and from 2014 to 2016 using a 1-mm multi-electrode-mapping catheter (PentaRay® group 2), was conducted. The endpoint was the complete elimination of late potentials (LPs), local abnormal ventricular activities (LAVA), and VT non-inducibility. Follow-up consisted of device interrogation to monitor for VT recurrence. Out of 74 VT patients aged 64.5 ± 12.0years (66 male [89.2%], 56 with ICM [75.7%], and 18 with NICM [24.3%)]), 48 patients (64.9%) were investigated in group 1 and 26 (35.1%) in group 2. Using the multi-point acquisition approach, a tendency to require less mapping time (group 1 65.2 ± 37.6min, group 2 55.6 ± 34.4min, p ns) was determined. During 12-month follow-up, 57 patients had freedom from VT recurrences (79.2%). The result was insignificant between the groups (38 patients (79.2%) in group 1 and 19 patients (73.1%) in group 2). In a single-center observational study, both conventional and high-density mapping approaches in VT patients are comparable in terms of procedure duration and outcome. Mapping time when using a multi-electrode catheter seems to have the tendency of being shorter. We should be encouraged to recruit more patients comparing the benefit of different catheter types.

Strategy and Outcome of Catheter Ablation for Persistent Atrial Fibrillation - Impact of Progress in the Mapping and Ablation Technologies.

Pulmonary vein (PV) antrum isolation (PVAI) is effective in treating paroxysmal atrial fibrillation (AF) but is less so for persistent AF. A recent randomized study on the ablation strategies for persistent AF demonstrated that 2 common atrial substrate modifications, creation of linear lesions in the left atrium and ablation of complex fractionated electrogram sites, in addition to PVAI did not improve the outcome compared with stand-alone PVAI, suggesting the necessity of a more individualized, selective approach to persistent AF. There are emerging technologies, including high-resolution mapping with the use of multi-electrode catheter and auto mapping system and contact force (CF) guide ablation; the former allows rapid and accurate confirmation of the completeness of PVAI, and the latter enhances the achievement of durable ablation lesions more securely. Ablation for fibrotic area(s) has been proposed as a new approach for substrate modification, and high-resolution mapping is useful to define the area with low-voltage electrograms, a surrogate marker for atrial fibrosis. Ablation for non-PV triggers in addition to PVAI improves the outcome of persistent AF. Further, durable isolation of the left atrial posterior wall may reduce AF recurrence. These ablation strategies with concomitant use of the emerging technologies are strongly expected to enhance the effectiveness of catheter ablation for persistent AF.

Multimodal Examination of Atrial Fibrillation Substrate: Correlation of Left Atrial Bipolar Voltage Using Multi-Electrode Fast Automated Mapping, Point-by-Point Mapping, and Magnetic Resonance Image Intensity Ratio.

Bipolar voltage mapping, as part of atrial fibrillation (AF) ablation, is traditionally performed in a point-by-point (PBP) approach using single-tip ablation catheters. Alternative techniques for fibrosis-delineation include fast-anatomical mapping (FAM) with multi-electrode circular catheters, and late gadolinium-enhanced magnetic-resonance imaging (LGE-MRI). The correlation between PBP, FAM, and LGE-MRI fibrosis assessment is unknown. In this study, we examined AF substrate using different modalities (PBP, FAM, and LGE-MRI mapping) in patients presenting for an AF ablation. LGE-MRI was performed pre-ablation in 26 patients (73% males, age 63±8years). Local image-intensity ratio (IIR) was used to normalize myocardial intensities. PBP- and FAM-voltage maps were acquired, in sinus rhythm, prior to ablation and co-registered to LGE-MRI. Mean bipolar voltage for all 19,087 FAM voltage points was 0.88±1.27mV and average IIR was 1.08±0.18. In an adjusted mixed-effects model, each unit increase in local IIR was associated with 57% decrease in bipolar voltage (p<0.0001). IIR of >0.74 corresponded to bipolar voltage <0.5 mV. A total of 1554 PBP-mapping points were matched to the nearest FAM-point. In an adjusted mixed-effects model, log-FAM bipolar voltage was significantly associated with log-PBP bipolar voltage (ß=0.36, p<0.0001). At low-voltages, FAM-mapping distribution was shifted to the left compared to PBP-mapping; at intermediate voltages, FAM and PBP voltages were overlapping; and at high voltages, FAM exceeded PBP-voltages. LGE-MRI, FAM and PBP-mapping show good correlation in delineating electro-anatomical AF substrate. Each approach has fundamental technical characteristics, the awareness of which allows proper assessment of atrial fibrosis.

Impact of number of co-existing rotors and inter-electrode distance on accuracy of rotor localization

BackgroundConflicting evidence exists on the efficacy of focal impulse and rotor modulation on atrial fibrillation ablation. A potential explanation is inaccurate rotor localization from multiple rotors coexistence and a relatively large (9–11mm) inter-electrode distance (IED) of the multi-electrode basket catheter. Methods and resultsWe studied a numerical model of cardiac action potential to reproduce one through seven rotors in a two-dimensional lattice. We estimated rotor location using phase singularity, Shannon entropy and dominant frequency. We then spatially downsampled the time series to create IEDs of 2–30mm. The error of rotor localization was measured with reference to the dynamics of phase singularity at the original spatial resolution (IED=1mm). IED has a significant impact on the error using all the methods. When only one rotor is present, the error increases exponentially as a function of IED. At the clinical IED of 10mm, the error is 3.8mm (phase singularity), 3.7mm (dominant frequency), and 11.8mm (Shannon entropy). When there are more than one rotors, the error of rotor localization increases 10-fold. The error based on the phase singularity method at the clinical IED of 10mm ranges from 30.0mm (two rotors) to 96.1mm (five rotors). ConclusionsThe magnitude of error of rotor localization using a clinically available basket catheter, in the presence of multiple rotors might be high enough to impact the accuracy of targeting during AF ablation. Improvement of catheter design and development of high-density mapping catheters may improve clinical outcomes of FIRM-guided AF ablation.

Ripple mapping: Initial multicenter experience of an intuitive approach to overcoming the limitations of 3D activation mapping.

Ripple mapping (RM) displays electrograms as moving bars over a three-dimensional surface displaying bipolar voltage, and has shown in a single-center series to be effective for atrial tachycardia (AT) mapping without annotation of local activation time or window-of-interest assignment. We tested the reproducibility of these findings in operators naïve to RM, using it for the first time in postablation AT. Maps were collected with multielectrode catheters and CARTO ConfiDENSE. A diagnosis of the tachycardia mechanism was made using RM and an assessment of operator confidence was made according to a three-grade scale (1 highest-3 lowest). The first 20 patients (64 ± 9 years, median two previous ablations) undergoing RM-guided AT ablation across five sites were studied. High-density maps (2,935 ± 1,328 points) in AT (CL=296 ± 95 milliseconds) were collected. Macroreentrant ATs bordered by scar or anatomical obstacles were identified in n=12 (60%), small reentrant ATs around scar in n=3 (15%), and focal ATs from scar in n=5 (25%). Diagnostic confidence with RM was grade 1 in n=13 (65%), where operators felt confident to proceed to ablation without entrainment. Ablation offered the correct diagnosis n=18 (90%). Retrospective review of the accompanying LAT maps demonstrated potential sources for error related to the window of interest selection, interpolation, and differentiating regions of scar during tachycardia on the voltage map. RM was easy to adopt by operators using it for the first time, and identified the correct target for ablation with high diagnostic confidence in most cases of complex AT.

Blood Pressure Response to Main Renal Artery and Combined Main Renal Artery Plus Branch Renal Denervation in Patients With Resistant Hypertension.

BackgroundSingle‐electrode ablation of the main renal artery for renal sympathetic denervation showed mixed blood pressure (BP)‐lowering effects. Further improvement of the technique seems crucial to optimize effectiveness of the procedure. Because sympathetic nerve fibers are closer to the lumen in the distal part of the renal artery, treatment of the distal main artery and its branches has been shown to reduce variability in treatment effects in preclinical studies and a recent randomized trial. Whether this optimized technique improves clinical outcomes remains uncertain. We report a 2‐center experience of main renal artery and combined main renal artery plus branches renal denervation in patients with resistant hypertension using a multielectrode catheter.Methods and ResultsTwenty‐five patients with therapy‐resistant hypertension underwent renal sympathetic denervation with combined main renal artery and renal branch ablation and were compared to matched controls undergoing an ablation of the main renal artery only. BP change was assessed by ambulatory measurement at baseline and after 3 months. At baseline, BP was balanced between the groups. After 3 months, BP changed significantly in the combined ablation group (systolic/diastolic 24‐hour mean and daytime mean BP −8.5±9.8/−7.0±10.7 and −9.4±9.8/−7.1±13.5 mm Hg, P<0.001/0.003 and <0.001/0.016, respectively), but not in patients with main artery treatment (−3.5±11.1/−2.0±7.6 and −2.8±10.9/−1.8±7.7 mm Hg, P=0.19/0.20 and 0.19/0.24, respectively). Systolic daytime BP was significantly more reduced in patients with combined ablation than in patients with main artery ablation (P=0.033).ConclusionsCombined ablation of the main renal artery and branches appears to improve BP‐lowering efficacy and should be further investigated.

P3979Using large-tip ablation catheter markedly decreases bipolar signal amplitude near spiral wave center but this is not the case with using multi-electrode mapping catheter: A simulation study

P3979Using large-tip ablation catheter markedly decreases bipolar signal amplitude near spiral wave center but this is not the case with using multi-electrode mapping catheter: A simulation study

Ablation as targeted perturbation to rewire communication network of persistent atrial fibrillation.

Persistent atrial fibrillation (AF) can be viewed as disintegrated patterns of information transmission by action potential across the communication network consisting of nodes linked by functional connectivity. To test the hypothesis that ablation of persistent AF is associated with improvement in both local and global connectivity within the communication networks, we analyzed multi-electrode basket catheter electrograms of 22 consecutive patients (63.5 ± 9.7 years, 78% male) during persistent AF before and after the focal impulse and rotor modulation-guided ablation. Eight patients (36%) developed recurrence within 6 months after ablation. We defined communication networks of AF by nodes (cardiac tissue adjacent to each electrode) and edges (mutual information between pairs of nodes). To evaluate patient-specific parameters of communication, thresholds of mutual information were applied to preserve 10% to 30% of the strongest edges. There was no significant difference in network parameters between both atria at baseline. Ablation effectively rewired the communication network of persistent AF to improve the overall connectivity. In addition, successful ablation improved local connectivity by increasing the average clustering coefficient, and also improved global connectivity by decreasing the characteristic path length. As a result, successful ablation improved the efficiency and robustness of the communication network by increasing the small-world index. These changes were not observed in patients with AF recurrence. Furthermore, a significant increase in the small-world index after ablation was associated with synchronization of the rhythm by acute AF termination. In conclusion, successful ablation rewires communication networks during persistent AF, making it more robust, efficient, and easier to synchronize. Quantitative analysis of communication networks provides not only a mechanistic insight that AF may be sustained by spatially localized sources and global connectivity, but also patient-specific metrics that could serve as a valid endpoint for therapeutic interventions.

Observational Study of Neural Respiratory Drive During Sleep at High Altitude.

Ventilation at altitude changes due to altered levels of pO2, pCO2 and the effect on blood pH. Nocturnal ventilation is particularly exposed to these changes. We hypothesized that an increasing neural respiratory drive (NRD) is associated with the severity of sleep-disordered breathing at altitude. Mountaineers were studied at sea level (London, United Kingdom), and at altitude at the Aconcagua (Andes, Argentina). NRD was measured as electromyogram of the diaphragm (EMGdi) overnight by a transesophageal multi-electrode catheter; results were reported for sea level, 3,380 m, 4,370 m, and 5,570 m. Four healthy subjects (3 men, age 31(3)years, body mass index 23.6(0.9)kg/m2, neck circumference 37.0(2.7)cm, forced expiratory volume in 1 second 111.8(5.1)%predicted, and forced vital capacity 115.5(6.3)%predicted) were studied. No subject had significant sleep abnormalities at sea level. Time to ascent to 3,380 m was 1 day, to 4,370 m was 5 days, and the total nights at altitude were 21 days. The oxygen desaturation index (4% oxygen desaturation index [ODI] 0.8(0.4), 22.0 (7.2), 61.4 (26.9), 144.9/hour, respectively) and the EMGdi (5.2 (1.9), 12.8 (5.1), 14.1 (3.4), 18.5%, respectively) increased with the development of periodic breathing at altitude, whereas the average SpO2 declined (97.5 (1.3), 84.8 (0.5), 81.0 (4.1), 68.5%, respectively). The average EMGdi correlated well with the 4%ODI (r = 0.968, p = 0.032). NRD sleep increases at altitude in relation to the severity of periodic breathing.

1156Early feasibility results evaluating a multi-electrode radiofrequency ablation balloon catheter system in patients with symptomatic paroxysmal atrial fibrillation

1156Early feasibility results evaluating a multi-electrode radiofrequency ablation balloon catheter system in patients with symptomatic paroxysmal atrial fibrillation

Diagnostic Perturbations.

Diagnostic Perturbations.

P1401Distributions and correlation of left atrial low voltage zone detected by high density multi-electrode catheter during atrial fibrillation and sinus rhythm

P1401Distributions and correlation of left atrial low voltage zone detected by high density multi-electrode catheter during atrial fibrillation and sinus rhythm

Online Measurement of Microembolic Signal Burden by Transcranial Doppler during Catheter Ablation for Atrial Fibrillation-Results of a Multicenter Trial.

Left atrial pulmonary vein isolation (PVI) is an accepted treatment option for patients with symptomatic atrial fibrillation (AF). This procedure can be complicated by stroke or silent cerebral embolism. Online measurement of microembolic signals (MESs) by transcranial Doppler (TCD) may be useful for characterizing thromboembolic burden during PVI. In this prospective multicenter trial, we investigated the burden, characteristics, and composition of MES during left atrial catheter ablation using a variety of catheter technologies. PVI was performed in a total of 42 patients using the circular-shaped multielectrode pulmonary vein ablation catheter (PVAC) technology in 23, an irrigated radiofrequency (IRF) in 14, and the cryoballoon (CB) technology in 5 patients. TCD was used to detect the total MES burden and sustained thromboembolic showers (TESs) of >30 s. During TES, the site of ablation within the left atrium was registered. MES composition was classified manually into "solid," "gaseous," or "equivocal" by off-line expert assessment. The total MES burden was higher when using IRF compared to CB (2,336 ± 1,654 vs. 593 ± 231; p = 0.007) and showed a tendency toward a higher burden when using IRF compared to PVAC (2,336 ± 1,654 vs. 1,685 ± 2,255; p = 0.08). TES occurred more often when using PVAC compared to IRF (1.5 ± 2 vs. 0.4 ± 1.3; p = 0.04) and most frequently when ablation was performed close to the left superior pulmonary vein (LSPV). Of the MES, 17.004 (23%) were characterized as definitely solid, 13.204 (18%) as clearly gaseous, and 44.366 (59%) as equivocal. We investigated the burden and characteristics of MES during left atrial catheter ablation for AF. All ablation techniques applied in this study generated a relevant number of MES. There was a significant difference in total MES burden using IRF compared to CB and a tendency toward a higher burden using IRF compared to PVAC. The highest TES burden was found in the PVAC group, particularly during ablation close to the LSPV. The composition of thromboembolic particles was balanced. The impact of MES, TES, and composition of thromboembolic particles on neurological outcome needs to be evaluated further. (Clinical Trial Registration: Deutsches Register Klinischer Studien, https://drks-neu.uniklinik-freiburg.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00003465. DRKS00003465.).

Challenges and Pitfalls of Entrainment Mapping of Ventricular Tachycardia: Ten Illustrative Concepts.

The use and interpretation of entrainment mapping, or continuous resetting, of a reentrant tachycardia has been regarded as the gold standard for delineation of the components of a reentrant circuit.1,2 The response during and after overdrive pacing, whereby 2 wavefronts enter the circuit antidromically (with fusion) and orthodromically, is used to confirm reentry as the arrhythmia mechanism and determine the relationship of the pacing site to the circuit. The fulfillment of classical criteria outlined by Waldo and colleagues3,4 were synthesized into an anatomic concept for scar-related ventricular tachycardia (VT) by Stevenson et al5 to portray the structural and architectural basis of circuit conduction meandering between regions of fibrosis. In this construct, a central corridor, or protected isthmus, is bordered between 2 regions of dense scar with a single entrance that is distinct from a single exit, which yields the QRS morphology.6 This reentrant model has been central to our current mechanistic understanding of scar-mediated VT and is critically important for differentiating critical sites from bystander sites and regions that are unlikely to interrupt or eliminate reentry.7 However, the nature of reentrant VT in man is more complex than our idealized working construct for many reasons. In clinical practice, the majority of VT is hemodynamically unstable, which precludes the ability to perform entrainment mapping and activation mapping of the entire circuit.8 Differences in the circuit between patients with untolerated and tolerated VT are not well understood. VT circuits are 3 dimensionally complex with transmural conduction and circuit conduction is unlikely to be planar, as depicted by electroanatomic mapping of the myocardial surface. Exits may be multiple9,10 and patterns other than loop reentry around scar are likely. Channels of preserved myocardium are frequently not “normal” in voltage (>1.5 mV) …

Downstream overdrive pacing and intracardiac concealed fusion to guide rapid identification of atrial tachycardia after atrial fibrillation ablation.

Atrial tachycardia (AT) related to atrial fibrillation (AF) ablation frequently poses a diagnostic challenge. Downstream overdrive pacing (DOP) can be used to rapidly detect reentry and assess proximity of a pacing site to an AT circuit or focus. We hypothesized that systematic DOP using multielectrode catheters would facilitate AT mapping. DOP identified constant fusion when the post-pacing interval (PPI)-tachycardia cycle length (TCL) <40 ms and stimulus to adjacent upstream atrial electrogram interval >75% of TCL. Mapping was performed as follows: (i) CS DOP, (ii) DOP at left atrial (LA) roof, (iii) DOP at selected LA sites based on prior DOP attempts, and (iv) mapping and ablation at regions of fractionated electrograms in region of AT. Activation mapping was performed at operator discretion. AT diagnosis was confirmed by successful ablation or additional mapping when ablation was unsuccessful. Fifty consecutive patients with sustained AT underwent mapping of 68 ATs, of whom 42 (62%) were macroreentrant, 19 were locally reentrant (28%), and 7 (10%) were focal. AT was correctly identified with a median of three DOP attempts. All macroreentrant ATs were identified with ≤6 DOP attempts. One AT (1.6%) was terminated by DOP, and three ATs (4.8%) required activation mapping. Intracardiac concealed fusion was seen in 26 ATs (38%), each of which was successfully ablated. Reentry could be demonstrated in a substantial majority of AF ablation-related AT. A stepwise diagnostic approach using DOP and recognition of intracardiac concealed fusion can be used to rapidly identify and ablate reentrant AT.

Catheter Ablation of Atrial Fibrillation: Where Are We?

Atrial fibrillation (AF) is the commonest cardiac arrhythmia, with significant morbidity and mortality. More than half of patients with AF are still symptomatic despite adequate anticoagulation and rate control. If antiarrhythmic drugs are ineffective or poorly tolerated, AF patients are then typically treated with catheter ablation to restore sinus rhythm. In the past 20 years, AF ablation has developed from a specialized, experimental procedure into a common treatment in the cardiovascular field. Various ablation techniques and mapping technologies have been described and are continuing to evolve for increased safety and efficacy. An incomplete list of such techniques and technologies would include focal and segmental, circumferential and linear, complex fractionated atrial electrogram, ganglionated plexus, focal impulse and rotor modulation, body surface potential mapping–guided, real-time MRI–guided, cryoballoon, visually guided laser balloon, radiofrequency hot balloon, contact force sensing catheter, multielectrode catheter, and hybrid ablations. This review examines the history of invasive AF treatment and its evolution into catheter ablation but mainly focuses on the discussion of various ablation techniques and technologies leading to our current understanding of the ablation therapy of this most common arrhythmia.